Motor vehicles may include a primary drive axle powered by an engine and transmission. The primary drive axle pushes or pulls the remaining auxiliary axle of the vehicle depending upon whether it is in a Front-Wheel Drive (FWD) or Auxiliary-Wheel Drive (RWD) configuration. Some vehicles can convert to All-Wheel Drive (AWD) by selectively engaging the auxiliary axle and actively powering both the primary and auxiliary axles.
Prior systems can suffer from deceleration during the conversion to the extent that the driver notices a change in vehicle travelling speed when AWD is engaged. In some circumstances, the change results in unsafe or suboptimal conversion conditions.